A Facile Synthetic Route to 1,1-Disubstituted 2,3-Dihydro-1<i>H</i>-benz[<i>f</i>]indene-4,9-diones
作者:Sitaram Pal、Bimal K. Banik、Usha Ranjan Ghatak
DOI:10.1055/s-1992-26304
日期:——
A facile synthetic route is described for 1,1-dimethyl and 1-methoxy-carbonyl-1-methyl substituted 2,3-dihydro-1H-benz[f]indene-4,9-diones 7a, 7c and 7d from the corresponding 1,2,3,4-tetrahydrofluorenes 2a, 2c, and 2d involving ruthenium-catalyzed periodate oxidation of the tetrasubstituted double bond to the respective 6,7,8,9,10,11-hexahydro-5,10-dioxo-5H-benzocyclononenes 3a, 3c and 3d, cyclization-dehydration (aromatization) and methylation to 2,3-dihydro-4-methoxy-1H-benz[f]indenes 6a, 6c and 6d, followed by oxidation with pyridinium chlorochromate/Celite. The only exception to this trend is 2b, which on ruthenium-catalyzed Periodate oxidation directly affords 7b
本文描述了从相应的 1,2,3,4-四氢芴 2a、2c 和 2d 到 1,1-二甲基和 1-甲氧基-羰基-1-甲基取代的 2,3-二氢-1H-苯并[f]茚-4,9-二酮 7a、7c 和 7d 的简便合成路线,其中涉及钌催化四取代双键的过硫酸盐氧化反应,生成各自的 6、7、8、9、10、11-六氢-5,10-二氧代-5H-苯并环壬烯 3a、3c 和 3d,环化-脱水(芳香化)和甲基化成 2,3-二氢-4-甲氧基-1H-苯并[f]茚 6a、6c 和 6d,然后用吡啶鎓氯铬酸盐/铈进行氧化。这一趋势的唯一例外是 2b,它在钌催化的高碘酸盐氧化作用下直接生成 7b